N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Characterization of n-on-p devices fabricated at ITC-irst Nicola Zorzi ITC-irst - Trento (Italy)

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors History SMART collaboration End 2003 finalized the layout May 2004 first batch of p-on-n devices on different substrates (FZ, MCz, Cz, EPI) Various samples sent for irradiation. August 2004 first batch of n-on-p devices with same layout Some samples sent for irradiation. January 2005 irradiated samples available for test

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Layout Test pads including diode, MOS, gated diodes, resistor, etc. 27 MG diodes 5 (pitch 50  m) + 5 (pitch 100  m) Microstrip detectors AC coupled, poly-resistor biased 10 Small MG Diodes Area 13.6 mm 2 die 6x6mm 2 Area 2.3 mm 2 die 4x4mm 2 die 6x47mm 2

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p batch # sub-type comments 3 FZ 525 p-spray 3E12 3 FZ 525 p-spray 5E12 3 FZ 200 p-spray 3E12 3 FZ 200 p-spray 5E12 6 MCz no OG; p-spray 3E12 5 MCz no OG; p-spray 5E12 FZ p-type >5000  cm 200  m MCz p-type >1.8k  cm 300  m FZ p-type >5000  cm 525  m

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p – IV on MG diodes (1) High dose p-spray Diode current (A) vs Voltage (V) GR current (A) vs Voltage (V) Leakage current ~ 10nA/cm 2 Measurements on 3 diodes per 8 wafers Breakdown voltage ~ V blue=FZ, red=MCz

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p – IV on MG diodes (2) Diode current (A) vs Voltage (V) GR current (A) vs Voltage (V) Leakage current ~ 10nA/cm 2 Breakdown voltage >1000V Low dose p-spray Measurements on 3 diodes per 9 wafers blue=FZ, red=MCz

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p – CV on diodes (1) Measurements on FZ wafers Depletion voltage very uniform at the wafer level.

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p – CV on diodes (2) Measurements on MCz wafers Doping concentration lower than n-type MCz (~2e12 against 7e12) but fluctuations of the same order Example of Doping profile from CV measurement

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p – CV on diodes (3) Probably due to fluctuations of the oxygen concentration. Quite high doping variations!!

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Microstrip minisensors AC coupled poly resistor biased die ~6x47mm 2

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Microstrip minisensors measurements BL&GR reverse IV (I_tot, V rev 0÷200 V) Strip current scan 100V V rev ) Bias resistors scan 100V V rev ) Capacitors scan 20V V cap ) pitch 50 µm 64 strips pitch 100 µm 32 strips probe-card + automatic prober

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors BL & GR I-V reverse currents (1) FZ wafers Low dose p-spray high dose p-spray MCz wafers high dose p-spray Low dose p-spray Bias-line 100 V

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors FZ wafers MCz wafers Bias-line 200 V BL & GR I-V reverse currents (2) Low dose p-spray high dose p-spray design dependence of voltage handling capability (pitch and …); low “break” voltage for high-dose p-spray; substrate dependence?

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Strip current scan (100V) Low current values on border strips Single strip I-V Floating strip potential high- and low-dose p-spray 50µm and 100µm pitch p and n substrates

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Bias resistor scan (100V) 37 squares width=6 µm Single strip I-V Single strip scan high dose p-spray Low dose p-spray Single scan uniformity: 0.2% ÷ 2% No results available for sensors with low breakdown values

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors AC-scan: ~23% sensors have broken capacitors (mainly 50µm pitch devices) Defects current-scan: only few sensors batch or sub problem? No AC-defects are present for p-on-n devices

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors Conclusion Problems on n-on-p production: non-uniformity of the depletion voltage (MCz subs) design/p-spray-dose interaction (  p-stop…?) To be verified: effectiveness of actual p-spray Samples available for the collaboration.

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p batch: samples # sub-type comments 3 FZ 200 p-spray 3E12 3 cut wafers 3 FZ 200 p-spray 5E12 2 cut wafers 6 MCz no OG; p-spray 3E12 3 cut wafers 5 MCz no OG; p-spray 5E12 3 cut wafers FZ p-type >5000  cm 200  m MCz p-type >1.8k  cm 300  m

N. Zorzi Trento, Feb 28 – Mar 1, 2005 Workshop on p-type detectors n-on-p – CV on diodes (3) More measurements on MCz wafers Quite high doping variations!! Map of the depletion voltages on three wafers.